1. Field of the Invention
The present invention relates to circular buffer, and in particular relates to a method and apparatus of a circular buffer for multi-rate data.
2. Description of the Related Art
Multi-rate data finds many applications in Digital Signal Process (DSP) systems, multimedia systems, computer systems, and telecommunication systems, in which data transmission at various data rates manages a wide variety of data types, formats, and rates. Temporary storage or buffers are commonly employed for multi-rate data, where precedent data are removed or overwritten upon processing of successive data.
While circular buffers have been deployed to buffer multi-rate data, optimization of buffer capacity remains a challenge. Third generation mobile telecommunications systems, such as Universal Mobile Telecommunications System (UMTS), require multi-rate data processing, wherein the data rate is adaptive with each frame.
U.S. Pat. No. 6,807,589 discloses a circular buffer for multi-rate data, employing four addresses indicating process status of previous data and calculating available buffer space by the four addresses, whereby successive buffer space can be allocated for successive data at a different data rate. However, the address maintenance and calculation increases circuitry complexity and manufacturing cost.
Therefore there is a need for a circular buffer with simple and efficient memory space allocation for data arriving at different data rates.